Classic Mustang

61 Excellent Tech Tips

These are tech tips seen on the web which were accumulated from many years of working different projects. They apply to just about any kind of 6 cyl or V-8.

Intake Heat Riser Crossover - The exhaust heat crossover through the head and intake is only needed if you are using a cast iron intake manifold. The crossover is there to heat the intake in cold weather so fuel will stay in suspension better. Since aluminum absorbs heat faster it is not necessary to have an auxiliary heat source like is needed cast iron. During warm weather the crossover is not needed, it just adds unnecessary heat to the intake charge. So for aluminum intakes, block the exhaust crossover to keep your manifold cooler and gain a little horsepower.

Exhaust Back - Pressure - Have you ever heard that it is necessary to have a little exhaust back pressure for an engine to run properly. What a bunch of crap!! The lower the exhaust back-pressure the better it will run. You can go too big on some components like a set of headers but this is wave tuning not back-pressure. Don't let anyone tell you that it takes back-pressure for an engine to run. The more back pressure the fewer horsepower.

Drill Press Valve Spring Tester - Have a set of valve springs that you want tested. Use a drill press and a standard bath room scale. Put the scale on the drill press table then use a set of calipers or tape measure to set the stop on the drill press at a certain height. Measure all the springs and record the scale reading. All springs should be within 10% of each other or the weaker ones should be replaced.

Cheap 16" Wheels - 1987 and 1988 Thunderbird Turbo Coupes have 16" aluminum wheels that can be bought for very cheap in want ads or at a junkyard. It seems that most people either love'em or hate'em. Many people run them everyday on their car and think they look great.

Door Crash Beams - Ever saw a strip only Mustang with the door crash beams removed for weight savings? This is alright for a strip only car with a side bar type roll bar but for the street - NO WAY!! Not only are they there for crash protection, but they give much needed rigidity to the sheet metal door skin. By the way - total weight savings is under 10 lbs. per door.

Aluminum vs. Cast Iron Heads - Many people don't pay attention to the compression ratio when going from cast iron to aluminum heads. Fact is that if everything was equal the cast iron head will make more power than an aluminum head. This is because the cast iron head doesn't absorb heat from the combustion process as fast at the aluminum head. Therefore more heat is available to push the piston down. The way to get back the lost horsepower is to up the compression on the aluminum head. Typically you can run about a half to full point more compression with an aluminum head over the cast iron.

Port Matching vs. Gasket Matching - Port matching is not the same as gasket matching. Port matching is lining up the ports on an engine so there is no abrupt wall change when going from the intake runners to the cylinder head ports. Gasket matching accomplishes the same thing but the ports will be opened up to the gasket size. Okay so what's the big deal? If you gasket match the port may go from small to big and back to small because it was opened up too big at the gasket surface. The bottom line is you might lose a little power by doing a gasket match instead of a good port match.

Tail Light Interchange - On Fox body Mustangs (1979-1993) the tail lights from the '79-82 Mustangs are all interchangeable, and the tail lights from the '83-93 are interchangeable. But the '79-82 sets will not change with the '83-93 sets - at least not a direct bolt-in because the holes in the tail light panel are different. Like anything else though you can get the sets to interchange with a set of tin snips, some spare sheet metal, a rivet gun, and some silicone.

Power Steering Racks and Pumps - '
79-84 Mustangs have a different power steering pump and rack than 85 and up V8 cars. The 79-84 racks are 2.5 turns to lock and the 85- racks are 2.25 turns to lock. If you upgrade to the 15:1 rack (85-) then also need to change out your power steering pump. The 15:1 racks have a higher pressure pump. If you use your existing pump you may experience a momentary lockup condition in a panic situation, i.e.: when moving the steering wheel real fast from one side to another. If you are auto crossing then this could be rather funny, if you are on the street then this could be rather deadly.

Granada Sway Bars - Eight cylinder 1976-80 Granadas have a front sway bar of about 1" in diameter. Turns out this bar has the same bends as a 1967-73 Mustang. As a cheap upgrade to the skinny Mustang bars, switch the Granada bar in its place.

Proper Ground When Relocating a Battery - When relocating your battery to the trunk for better weight distribution be sure to run the ground wire all the way back to the engine block. Don't just run a strap straight to the frame. This will save you a ton of headaches. The resistance thru the frame is higher than thru the cable. This will make a difference when starting your car. Use at least 2-gauge wire for both the positive and negative sides. Also run a good ground strap between the engine block and the firewall.

Long Rods (289) - What a cheap long rod engine? Use 289 rod (5.156" long) in place of the 302 rod (5.090" long). The 289 rod is about a 1/16" longer than the 302 rod. You can use standard 302 pistons and mill off the tops to get the deck height you want. This not only gives you a long rod engine but also a lighter piston that moves the ring pack up for better combustion.

Big Sway Bars / Spring Matching - I once tried to run a big sway bar on the front of my Stang. The handling was terrible, if I took a turn too fast the front tires would start to hop violently. The problem was that the springs, sway bar, and struts were not properly matched. Moral of the story is to match the suspension components like you would a good engine combination for best results.

Extending The End Links on the Front Sway Bar - On a street / strip car don't remove the front sway bar for street driving. Instead extend the end links about 1.5"-2" on each side to allow the front to pickup higher and transfer more weight to the rear at the track. Removing the sway bar can make your car unstable, by extending the links the bar will still work properly.

It's the Sum of the Parts (Combination Matters) - Can you believe that after all that has been written about not mismatching parts that people still do it. Analyze your combination before buying parts. Purchase parts that fit together and enhance the car's performance.

Use Pilot Bearing, not Bushing - To decrease the wear on your transmission shaft use a pilot bearing not a bushing. The bearing is a small roller bearing that goes in the end of your crank. A manual transmission's input shaft fits into the bearing for support. The bushing does the same function but without the roller bearing. It operates more like a journal bearing. So for less wear and tear ask for the bearing not the bushing.

Use the Right Size Carburetor - The formula for carburetor sizing is: cfm = (CID) X (max. RPM) X (V.E.) / 3456. Where V.E. = volumetric efficiency. For a race motor use a V.E. of 1.1, for the street use 0.9. So for a 302 with a red line of 6,000 rpm on the street only needs 471 cfm (302*6000*0.9/3456), more than enough for a 600 cfm carb to provide.

Stock Cam is Good - The stock 87-93 Mustang cams are actually pretty good. They can provide great driveability, idle smoothly, good gas mileage, and can run in the 12s at the strip. But don't get me wrong there is room for improvement, just don't make a cam change your first mod.

10" Rear Drums - Many Fairmonts, especially the wagons, came with 10" rear drum brakes. Mustangs only came with 9" drums. For a little more stopping power switch to the 10" drums. Be sure to get the other brake components and backing plates with the drums for an easier switch.

Big Cams and Compression Ratios - Ever seen someone install a big cam and not get the results they thought they would? There is a reason why the cam manufacturers list the recommended compression ratio in their catalogs. With a big cam comes lots of overlap which means cylinder pressure bleed off. Up the compression to find that lost horsepower.

Computer Simulations - Computer simulations are a great way to try out your ideas before you spend the money. Remember though the output is only as good as the input, that is why you must perform some testing and refine your computer models for the best results.

Windage Tray - When looking for horsepower improvements almost all the go fast goodies are related to the induction and exhaust. So what can you do to the short block to improve speed. The easiest thing is a windage tray. A windage tray attaches to the main cap bolts and keeps the oil mist found in the oil pan under control. Imagine how much easier it is for your crank to spin in air instead of the thick air / oil mixture. Expect an improvement of about 15+ Hp for a typical street car.

Be Prepared When Going to the Track - I always make a list a goodies to take to the track well in advance of packing up. All I have to do is just gather up what's on the list instead of thinking about what I need and possibly forgetting something. My list includes the goals and objectives of my trip (i.e. what I am trying to test or achieve) and a list of tools and parts.

Local DynoJet
Every major city now has a DynoJet chassis dyno. Find out where yours is and how much it costs. My local guy only charges $50 for three runs. This is pretty cheap for such a fantastic tuning tool. Be sure you are prepared before you go to know what you will change for each run, that a way you are not scrambling when you get there and forget something.

Having a Game Plan - Before you begin any project rather little or big make sure you know where you’re trying to end up. By not having a clear vision of your projects goals you can get easily side tracked then eventually lose interest. Take time to thoroughly plan out what you are trying to achieve and how you plan to get there before ever buying the first part or turning the first wrench.

Underdrive Pulleys - Underdrive pulleys work. They are always worth about 5 - 15 horsepower depending on the set you get. It just makes good sense. This should be one of the first changes that every Mustang owner does.

Ram Air - By ducting cold air to the carburetor inlet you can pick up a few horsepower over the hot air typically in the engine compartment. By taking a hood scoop and sealing the pressurized cool air being picked up by the scoop directly into the engine you can pick up a little more. Elapsed time improvement is about a tenth or two in the quarter for a typical 13-second street vehicle.

Drag Tires (The importance of Traction) - I never realized how important traction was until I began making passes at the strip. Good slicks on a stock Mustang can easily make a 1/2-second difference in the quarter mile over street tires. A good cheap setup for a street / strip car is to put some McCreary or M&H G60-15 tires on a set of used factory 15" rims. The tires are about a $100 each and the rims can be had for under $50. Total cost for a huge e.t. improvement is about $250.

Concentration - The best and most consistent drag racers go thru the same routine every time. They do the same burnout, stage the same, watch the tree the same way, and shift the same. This helps them concentrate - gets them in the groove each time. Develop a routine that works for you and stick to it. Before long you'll be concentrating on the right things just like it is second nature.

Marking the Shift Point on the Tach - During the heat of battle it can be hard to hit the right shift point every time. The best thing to do is to cut an 1/4" wide piece of tape and place it on your tach face where you want to shift. You'll find it easier to concentrate on the tach needle lining up with the tape, than lining up with a number.

Using the Stock Tach - The stock Mustang tach is said to be highly inaccurate. So What!! The factory tach is repeatable meaning that it is always inaccurate the same amount. When finding the right shift point don't worry about what the rpm the tach says just go to the correct mark on the tach. It doesn't matter if the tach reads 5,600 rpm and you are really at 6,000 rpm as long as you find the optimum shift point and nail it.

28 Spline Axles - Stock Mustang axles seem to be getting close to their breaking point at about the mid-12 second mark in the quarter, especially if you are launching hard and using slicks. A simple upgrade to an aftermarket 28 spline axle may be a good solution for you. Aftermarket axles can handle cars down to the high 11s without a problem. Faster than this then you would be wise to upgrade to a 31 spline or better.

Clutch Fan or Electric Fan - For a performance engine there is only two options for the engine fan - either clutch fan or electric. A flex fan wastes horsepower whenever the car is moving fast enough to provide sufficient air flow for cooling. The worst fans of all are the lightweight plastic fans - definitely stay away from those. So in order of best to worst, electric fan, clutch fan, steel flex fan, solid fan, plastic.

Lifter Valley Tray (Fuel Injected Engines) - The cooler the intake charge the more horsepower. One way to a cooler intake charge is to have a cooler intake manifold. By blocking the hot engine oil on the lower part of the intake runners the intake will remain cooler therefore the charge air will pick up less heat. A lifter valley tray can be made at home using a piece of sheet metal the same size as the bottom of the intake manifold. Fix it to the bottom of the intake with sheet metal screws. Hot oil will splash onto the sheet metal not the intake runner and fall back into the engine. Make sure you have sufficient clearance between the tray and the valve train to prevent unwanted failures.

Drag Racing Safety Equipment - Every racing sanctioning body has some type of safety equipment requirement you must meet before you can compete. The reason - to protect those not smart enough to get the proper safety equipment on their own. If you don't play by the rules then just stay at home. It is like a seat belt or helmet law - there to protect those not smart enough to protect themselves.

Baffling the Stock Pan - Adding baffles to the stock oil pan to keep more oil around the pickup during acceleration, braking, or cornering is easy. What you are trying to prevent is oil from climbing up the side or back of the pan and uncovering the pickup. Take 1" wide sheet metal strips and weld them to the sides of the pan all around the sump area just above the oil level. Now the oil will try to climb the walls of the sump only to met with the baffles and be redirected back toward the pickup.

Best Book Ever - Slot Car Mustang Handbook - When I first read excerpts from this book in Super Ford magazine back in the early 90s I knew this is what I wanted. I had to pay $25 for a copy and wait six weeks for delivery from Slot Car Mustangs in Houston, TX. Well it turns out it was worth the wait. Sometime later the book was updated and mass-produced under the title Mustang Performance Handbook, Volume Two. This is one of the best books ever written when it comes to the Ford Mustang, and a must have for any corner carver or drag racer.

Lincoln LSC Calipers - Upgrading 10" front disk brakes with the later 11" ('87 and up V8) rotors will help shorten stopping distances. You need the master cylinder, rotors, calipers, brake lines, and spindles. You can use your same struts but the bolt spacing where the spindle bolts up and the spindle width are different, so be prepared to do a little grinding and get some washers to take up the slack. While your at it upgrade to the '84-'92 Lincoln LSC calipers. They have a larger bore vs. the stock Mustang 11" brakes (73mm vs. 65mm). Be sure to match the correct Lincoln master cylinder for optimum results.

Lightweight Carpet - Production cars have a lot of sound deadener, by removing this your car will be a little noisier inside but you can save about 30+ pounds. While you’re at it buy some of the cheap lightweight universal replacement carpet at your local auto store. This stuff weighs quite a bit less than the stock carpet. Cut and form-fit it into place for an additional 10-pound saving.

Moroso Cool Can - A cool can is a device the cools the incoming fuel before it enters the carburetor. Typically it is a canister filled with ice and mounts under the hood. The fuel line routes thru the canister after the fuel pump and before the carb. Cooler fuel cools the intake mixture, which equals more horsepower. This is one tip that does nothing for you on the street but can make a difference at the strip.

T-Bird / Mustang Quad Shocks - Quad shocks work great to control wheel hop, but often times they are too close to oversized tires to provide adequate clearance. Small differences between makes and models can give you an extra 3/4"-1" tire clearance. The Mustang quad shocks and T-Bird mounts give the best combination. The Mustang quad shocks are flattened instead of round for extra tire clearance. The T-Bird mounts go under the subframe instead of the side. When combined together you get a little more clearance.

Lightweight K-Member - 1986 thru 1993 front K-members are about 10 pounds lighter than 1979 thru 1985 K-members. Also the 1993 versions have a revised geometry to make the car not dive as much during hard braking.

Boss 429 Scoop - Looking for something a little different? The 1969-70 Boss 429 hood scoop will fit fox Mustangs and look great. When used in conjunction with a hole thru the hood for air cleaner clearance you can gain about 3 inches of clearance under hood.

Rear End Vibration Damper - That heavy bone shaped thing on the front of the rear end snout is the factory vibration damper. Each one is tuned to a frequency that corresponds with the factory gear ratio to cut down on noise, vibration, and harshness (NVH). Turns out the thing is no longer at the proper frequency if you changed the rear end gear ratio. Take it off and throw the bottom bone shaped part in the nearest trash can. Keep the top sheet metal part and reattach it to the rear end with some shorter bolts. This gives the pinion snubber something flat to hit against.

Polishing the Crank Journals - A simple way to polish small imperfections from the crank journals is to use sandpaper and a shoestring. Cut a strip of 600-grit wet/dry paper the same width as the journal. Wrap the paper around the journal. Then wrap the shoestring around the paper a couple of times. Pull back and forth on the shoestring until the journal is polished.

Engine Tie Down Turnbuckle - Ever rev you engine up and looked at how much it twists on the stock mounts. That is wasted horsepower that could be delivered to your rear wheels. Get a simple turnbuckle and a few links of chain from the local hardware store. Make a strap between the head and your front frame rail on the driver’s side. Tighten the engine down. This will increase the vibration inside the car a little during normal cruising but it will also make it much less likely that you will ever break a motor mount.

Making Solid Motor Mounts - Many stock fox body motor mounts contain a rivet to hold them together incase the rubber fails. Drill this out and replace with a flat head screw and lock nut to get a pseudo solid mount. You have the benefits of the solid mount but less vibration transmitted to the chassis.

When to Use a Solid Tranny Mount - Only use a solid tranny mount when you have the engine properly secured in place. Properly secured includes solid motor mounts or the pseudo solid mounts and a turnbuckle listed above.

Drive shaft Length - There are basically 3 factory drive shaft lengths available for Fox Mustangs. The longest is the 4-cylinder with a 7.5" rear end. The next shorter by about 1.5" is the V8 and 7.5" rear end. The shortest is the V8 and the 8.8" rearend combo that is still another 1" shorter. When doing an engine swap plan on getting your drive shaft cut and rebalanced (about $90). The length you are looking for is 45.5" from center to center of the U-joints. This length will work for any 1979-1995 Mustang / Capri 5.0L with T5 / SROD / C4 / AOD transmission and either a 7.5" or 8.8" rear end.

Pinion Snubber - Using a pinion snubber to control the pinion angle during a hard launch is one way of increasing traction and controlling wheel hop. Build or buy an adjustable pinion snubber for mounting above the front snout on your car's rear end. Optimum pinion angle is typically about 4° down.

Class Racing - Ever keep up with the Fun Ford Weekend or National Mustang Racers Association (NMRA) classes. It is amazing at how fast these guys can run. I typically keep up with some of the milder stock classes, i.e. Real Street, Pure Street, Trophy Stock, and Factory Stock. Find a set of rules that closely fits your combo, then look at the times these guys run. It will give you something to shoot for.

Brakes Can Slow You Down - Try this experiment sometime, jack one of your front wheels off the ground and rotate it with your hands. Does it spin freely or is there a substantial amount of drag? If you give it a good spin does it continue to spin when you let go or will it quit almost instantly? This is drag from your brakes and any amount will slow you down and hurt your gas mileage. To fix the problem on the front, check to be sure your discs are not warped, use solid caliper bushings to keep everything better aligned, and make sure the pads are releasing from the rotor properly. On the rear brakes, check the drum to shoe alignment, back off your self-adjusters a little, and make sure the shoes are releasing properly. One last trick on the rear is to add a touch of high temp grease where the shoe rids against the backing plate. But don't get any on the pads themselves you still want the brakes to work.

How Much Oil? - Overfilling the engine with oil will cost you a bunch of horsepower. Whenever you build your next engine make sure the 'full' mark on the dipstick is below the crank rotating assembly. An old bracket racer trick is to only use four quarts in the stock pan vs. five to reduce windage - good for limited use on the track but don't try it on the street.

Which Cars are Foxey - The term Fox was the Ford internal code name for the new type of chassis that became a 1978 Fairmont. Since then a number of different Ford cars use the same basic chassis design. They are the 1978-82 Fairmont / Zephyr, 79-93 Mustang, 79-86 Capri, 80-88 T-Bird / Cougar, 81-82 Granada / Monarch, 83-86 LTD / Marquis, and 84-92 Lincoln Mark VII. Often times many of the parts will swap from one fox type vehicle to another. In 1994 Ford revised the Mustang to the Fox-4 chassis which is basically a stiffer and refined Fox type chassis. Ford still uses the Fox-4 chassis as of this writing in early 2001.

Push Rod Length Tool - Often times it is necessary to get a set of custom length pushrods. To determine the length you can purchase a tool or make one yourself. Take an old pushrod and cut it in half then cut an additional inch from one of the two pieces. Thread the inside of each end with a #10-24 tap. Use a 2" piece of #10-24 all thread to put it back together. Adjust the push rod length to the correct size by twisting the two halves together.

Always Change the Oil and Filter - Ever heard of someone just changing the filter and adding a quart back to the system? Or changing the oil without changing the filter? Not a good idea. Whenever you change your oil change both the filter and oil. Also beware of oil change places - many, not all, but many have a tendency to over-tighten your oil pan screw thus striping it out. If you are not a DIY type of person then ask around and find a good reputable shop before dropping off your Stang.

Worth More than a Nickel (How to Check Tread Depth) - Take a nickel with the top of Thomas Jefferson's head closest to the tire and insert it between your tire tread. If the tread comes up to the top of his head then your okay. If not, then time to replace those tires.

How Big of Rear Tire? - Everybody always wants to know how big of rear tire can they put under a 79-93 Mustang. Well usually a P265/50-15 is about the limit. With rolling of the quarter panel lip and use of a large hammer on the inner fender you won't have any problems rubbing, even on the biggest bumps. For a drag slick a 28x10.5 will fit with the same clearance mods. In both cases forget using quad shocks - they won't fit.

Aftermarket Oil Pressure and Temperature Gauges - The stock gauges on most cars are slow to react and highly inaccurate. I replaced mine with Stewart Warner gauges. Things to look for in a good aftermarket gauge are a full 270°-indicator movement, price, and name brand. Good gauges are expensive. This is one part that you get what you pay for.

Alternator Cutout - An old drag racers trick is to put a switch on the alternator charging circuit to turn off the current right before a race. With no charging being done then electrical drag is reduced. Just don't forget you have it off at the end of the race or you won't have a charged battery. Expect about a 5 Hp gain.

Tie Into the Seat Belt Mount - Roll bars that tie into the upper seat belt mount not only have the advantage of having two extra mounting places, but also are much stronger. The upper seat belt mount is a very strong place in the frame. By tying the roll bar in there the amount of stress on the bar and chassis will help the car twist less and be much more rigid in case of roll over.